Following a lower limb injury or trauma like sprains, strains, contusions, denervated muscle, articular surgery or amputation, the force of the legs is severally impaired so that the injured person often has to perform physical therapy to regain functional control of their lower extremities. Physical therapy or rehabilitation of lower limbs usually requires the presence of a physical therapist at the bedside of the patient to provide postural cues and general strengthening of muscles thought to aid in desired motion or control faulty movement pattern. Indeed, during the first steps of the therapy, some patients are even not able to move their legs lying on a bed because the surface of the bed provides too much friction or resistance for proper lateral movement of their legs.
In the past, various exercise machines have been designed to mimic the functional movement of the legs, such as abduction, adduction, extension or flexion of the legs. However, these machines impose a significant resistance to the movement of the lower limbs so that a person with severe reduction of leg strength would not be able to use. Moreover, these machines are generally configured for only one type of movement with a limited range of motion in abduction, adduction, extension or flexion of the legs. They generally involve cumbersome and expensive equipment that are not adaptable for home use.
In particular, U.S. Pat. No. 4,625,960 (Gvoich et al.) teaches an abductor-adductor exercise device that is portable. This device comprises a pair of knee rest movable in a lateral direction along a straight rail in response to the movement of the legs. The operation of the device is based on the cushioning effect of air by adjusting the resistance of the unit. Such complex assembly of a resistance system, including air cylinders, pistons and valves, unnecessarily increases the weight and the fabrication cost of a unit. More importantly for the patient, since the rail is a straight line, this device provides a limited range of motion in abduction or adduction.
The Chinese application no. CN 104546381 (Rongjuan et al.) teaches a similar device than Gvoich et al. with a pair of support members movable in a lateral direction along a straight rail. However, the movement of the support members is powered by a motor oil pump, which also increases the weight and the fabrication cost of a unit.
Therefore, there is a need to provide a physical therapy device for lower limbs that is affordable, portable and adaptable for home use or at the bedside of a patient, which also adapted to allow for a full range of motion with minimum resistance in abduction, adduction, extension or flexion of the legs.